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When to plant in Arcata, CA

USDA Zone 9b

Everything below — frost dates, hardiness zone, and what to plant when in Arcata, California — is derived from the closest NOAA station with complete climate normals.

With about 288 frost-free days, Arcata supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. Zone 9b is warm enough that Arcata can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · EUREKA WFO WOODLEY ISLAND · 9.3 km
Last spring frost
February 22
50% chance · 32°F
First fall frost
December 7
50% chance · 32°F
Growing season
288 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for ArcataA year-band showing 32°F frost risk from January to December for Arcata: last spring frost around February 22, first fall frost around December 7, about 288 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average last spring frost in Arcata is now 7 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

EUREKA WFO WOODLEY ISLAND · 1991–2020

The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Arcata’s own odds, recorded at EUREKA WFO WOODLEY ISLAND.

Frost-probability curves for ArcataProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around February 22 and the first fall frost around December 7, giving about 288 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FApr 22Apr 1Mar 1Oct 25Nov 12Dec 4
32°FMar 23Feb 22Dec 31Nov 15Dec 7Jan 11
28°FFeb 8Jan 3Dec 11Dec 3Dec 25Jan 29

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19

Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.

Add the next planting windows to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in Arcata, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 42 km · complete 32°F normals

When stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.

EUREKA WFO WOODLEY ISLAND
Primary
9 km · 6 m elevation
SPRING
Feb 22
FALL
Dec 7
ARCATA EUREKA AP
13 km · 61 m elevation
SPRING
Mar 8
FALL
Nov 30
SCOTIA
42 km · 42 m elevation
SPRING
Feb 1
FALL
Dec 19

Arcata planting FAQ

When is the last spring frost in Arcata, CA?

Plan for the last spring frost in Arcata around February 22 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.

When is the first fall frost in Arcata, CA?

Expect Arcata's first fall frost near December 7 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.

What hardiness zone is Arcata in?

Arcata is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.

How long is the growing season in Arcata?

There are roughly 288 frost-free days in Arcata (a long growing season), running from the average last frost around February 22 to the first fall frost near December 7.

When should I plant tomatoes in Arcata?

In Arcata, start tomato seeds indoors around December 28–January 11, then transplant seedlings outdoors around March 1 once the danger of frost has passed.

Planting reminders

Never miss a window in Arcata

An email when it’s time to start seeds, transplant, and sow — timed to Arcata’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at EUREKA WFO WOODLEY ISLAND, 9 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in Arcata, CA — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00024213. Retrieved from https://blissgarden.com/california/arcata.
When to Plant in Arcata, CA — Frost Dates & Zone 9b — BlissGarden